Pieree basmaisow



P. BASMAISON.

' EXTENSION BIT.

APPLICATION NLED IULYlBMIQIB.

1 323,570. I Y Patented Dec. 2, 1919.

ll .f TED STATES PIERRE BASIVIAISON, OFSAN FRANCiES CO, CALIFORNIA.

nXrnNsroiv-Brr.

Application filed J1i1y l8, 1918.

To all whom it may concern: 7

Be it known that I, PIERRE BAsMAISON, a citizen of the United States, residing in the city and county of San Francisco, State of California, have invented ful Improvement in Extension- Bits, of which the following is a specification.

My invention relates to improvements in extension bits wherein a pair of bits operate in conjunction with a drill or other suitable center; and the objects of my invention are V First, to provide an inip' roved extension bit having improved means for regulating the cutting depth thereof whereby said cutting depth may be regulated to hard or soft improved extension bit, the

material and so that the chips cut by the bit will be of uniform thickness in order to minimize liablity to breakage of the bits;

Second, to provide an improved arrangement for facilitating the sharpening of the cutting edge; b

Third, to provideian improved bit having an inclined or slanted cutting edge to produce a greater cutting surface; 7 Fourth, to provide an improved device of the class described having improved means whereby a tapered plug may be cut from the material being worked; and

Fifth, to provide an improved extension bit adapted to bore a hole without cutting through the entire contents or area of the hole diameter.

accomplish these several objects by means of the device disclosed in the drawings forming a part of the present 'specifica tion wherein like characters of reference are used to designate similar parts throughout the said specification and drawings, and in which 7 Figure 1 is a broken side elevation of my dotted lines indicating another position of the bit;

Fig. 2 is a broken front elevation of Fig. 1; b 7

Fig. 3 is a broken plan view of Fig. 2;

Fig. 4 is a broken side elevation of a modified from of the invention;

Fig. 5 is a plan view of a hole and channel as bored by the modified form disclosed in Fig. 4;

Figs. 6 and 7 are enlargedbroken Ends and front elevations, respectively, of the bit and the limiting gage removed from the device;

Specification of Letters Patent.

a. new. and usepending bored.

.with" a beveled therein secured by Patented Dec. 2, 1919. Serial No. 246,254. 7

Fig. 8 is a bottom an V b Fig. 9 is an enlarged broken view of a lionodified form of a cutting portion of the it. i

Referring to the drawings the numeral 1 is used to designate a suitable vertically disposed stem squared as at 2 to facilitate attachment to a brace or chuck, not shown.

In the preferred form of the invention the stem 1 is provided with a hollow deextension 3 provided with longi tudinal slots 4 through which pro ect the ends ofa lateral pin 5 carried by a vertically disposed conical pivotal point 6 slidably mounted within the hollow extension 3and having an annular flange or shoulder 7 rotatably mounted upon the, bottom thereof to limit the projection of said point thereof into the wood or material being A suitable spring 8 is interposed between the ends of the pin 5 and a second pin 9 secured to the upper end of the extension 3, the whole constituting a resiliently yielding pivotal point for the support of the device.

A bar or member 11 is slidably' mounted to move horizontally within the stem 1 and is provided with a longitudinal groove 12 which is engaged by a suitable securing screw 14: within the stem 1 to prevent longitudinal and rotary movement of said bar. A head 1h is mounted or secured toone end of the bar 11 which head 16 is provided groove 17 and a plate 18 a screw 19, said plate 18 being'provided to secure a bit 20 and a limiting gage 21, which are so connected by means of a tongue and groove 22 as disclosed in Fig. 3 of the drawings, as to be adapted to slide longitudinally upon each other.

Referring to Figs. 7 and 8 of the drawing it will be seen that the bit 20 is provided with a cutting edge 23 which is inclined relatively to any diameter of a hole being bored whereby a greater cutting edge or area is obtained. The forward point of the cutting edge 23 is near the pivotal point while the rear end of the said cutting edge 23 is on the outer point of the periphery of the cutting circular so that a slicing effect is obtained which will produce a greater efliciency in removing the shavings or chips.

The bit 20 is also provided With a slight plan view of Fig. 7;

concavity 2 5 on the outer side or surface thereof which leaves an aperture'between said bit 20 and the outer surface of an annular channel or hole being bored through Which the shaving passes as the bit 20 moves forward. The bit 20 is provided with the usual scoring cutter 24:.

The gage21 isarranged in front of the bit 20, and the bottom of the gage is slightly inclined and extended in advance of and above the cutting edge 23 of the bit, as disclosed in Fig. 7 of the drawings and the gage is also provided with an arcuate or concave part 27, which, when'the gage has made a complete revolution and encounters removal of the shav ng from the'path by the gage. V

In Fig. i, I have disclosed a modified form of the invention wherein the extension 3, secured by the screw 30, has been replaced by a drill 31. Bymeans ofthis modified form a hole may be bored without cutting through the entire contents as embraced by the circle or diameter of the hole being bored.

As the stem 1 is rotated the bit 20 and the gage 21 perform their function and simultaneously the drill 31 bores a central hole thus providing a turning point or hearing for the bit 20 and the gage 21.

In Fig. 9, I have disclosed a further modification wherein the bit 20 is provided with a vertically disposed and slanted inner cutting edge 3 1- by means of which a tapered plug of any diameter may be cut when the bit 20 and the gage 21 are used in conjunction with the resiliently yielding pivotal point 6.

By moving the gage 21 longitudinally of the bit 20 the distance between the lower surface of the gage 21 and the cutting edge depth of the bit maybe easily- 28 of the bit 20 may be regulated and adjusted to cut a greater or lesser depth of Width of shaving. In hard woods and other hard material a-thinner shaving is removed by the gage than when boring in softer materials.

Therefore it is obvious that the cutting and readily adjusted and that the shavings cut by the bit Will be of uniform thickness. It is also evident that the gage will minimize liability to breakage of the bit'by being in advance of the bit and thus preventing the bit from digging into the material, in which it isoperat'ing; and by removing the shavings from the path of the bit.

The feature of slidably connecting a'lim- 7 iting gage with a bit presents a further advantage n thatthe gage and-the bit may be separated to facilitate access tothe cutting edge 23when same isto be sharpened.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is 1. In an extension bit having a stem. .a

bit secured to the stem and arranged par- .allel therewith; and a lmntlng gage secured to the stem and arranged parailel with and in front of thebit and being slidable longitudinally upon the bit, the bottom of the gage being inclined. and extended in advance of and above the cutting edge of the bit.

2. In an extension bit having a stem, a bit secured to the stem and arranged parallel. therewith; and a limiting the stem and arranged parallel with and in front of the bit and being slidable longitudinally upon the bit the gage having in front thereof a concave part which causes the removal of shavings from the path of.

the bit when the gage encounters the shavings, V clmed and extended in advance of and above the cutting edge of the bit.

In witness whereof, I hereunto set my signature.

PIERRE BASMAISON.

gage secured to and the bottom ofthe gage being in- 

